///
// * jdbm LICENSE v1.00
// *
// * Redistribution and use of this software and associated documentation
// * ("Software"), with or without modification, are permitted provided
// * that the following conditions are met:
// *
// * 1. Redistributions of source code must retain copyright
// *    statements and notices.  Redistributions must also contain a
// *    copy of this document.
// *
// * 2. Redistributions in binary form must reproduce the
// *    above copyright notice, this list of conditions and the
// *    following disclaimer in the documentation and/or other
// *    materials provided with the distribution.
// *
// * 3. The name "jdbm" must not be used to endorse or promote
// *    products derived from this Software without prior written
// *    permission of Cees de Groot.  For written permission,
// *    please contact cg@cdegroot.com.
// *
// * 4. Products derived from this Software may not be called "jdbm"
// *    nor may "jdbm" appear in their names without prior written
// *    permission of Cees de Groot. 
// *
// * 5. Due credit should be given to the jdbm Project
// *    (http://jdbm.sourceforge.net/).
// *
// * THIS SOFTWARE IS PROVIDED BY THE ndbm PROJECT AND CONTRIBUTORS
// * ``AS IS'' AND ANY EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT
// * NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
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// * CEES DE GROOT OR ANY CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
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// * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
// * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
// * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
// * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
// * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
// * OF THE POSSIBILITY OF SUCH DAMAGE.
// *
// * Copyright 2000 (C) Cees de Groot. All Rights Reserved.
// * Contributions are Copyright (C) 2000 by their associated contributors.
// *
// * $Id: PageCursor.java,v 1.1 2000/05/06 00:00:31 boisvert Exp $
// 

//*************************************************************************
//**  Included in JDMB 1.0 port to SharpDBM;  11/2013 Cyrus Neah cneah@codingreal.com
//**  SharpDBM is an independent reimplementation of the JDBM 1.0 software library in C#  
//*************************************************************************


using SharpDBM.helper;

namespace SharpDBM.recman
{


///
// *  This class provides a cursor that can follow lists of pages
// *  bi-directionally.
// 
	internal   class PageCursor
	{
		internal PageManager pageman;
		internal long current;
		internal short type;

//    *
//     *  Constructs a page cursor that starts at the indicated block.
//     
		internal PageCursor(PageManager pageman, long current)
		{
			this.pageman = pageman;
			this.current = current;
		}

//    *
//     *  Constructs a page cursor that starts at the first block
//     *  of the indicated list.
//     
 
//
		internal PageCursor(PageManager pageman, short type)
		{
			this.pageman = pageman;
			this.type = type;
		}

//    *
//     *  Returns the current value of the cursor.
//     
 
//
		internal virtual long getCurrent()
		{
			return current;
		}

//    *
//     *  Returns the next value of the cursor
//     
 
//
		internal virtual long next()
		{
			if (current == 0)
				current = pageman.getFirst(type);
			else
				current = pageman.getNext(current);
			return current;
		}

//    *
//     *  Returns the previous value of the cursor
//     
 
//
		internal virtual long prev()
		{
			current = pageman.getPrev(current);
			return current;
		}
	}

}